Mandibular advancement splint for the treatment of obstructive sleep apnea

Abstract

Mandibular Advancement Splint (MAS) is a simpler alternative to continuous positive airway pressure (CPAP) for the treatment of mild and moderate OSA. The aim of the study was to evaluate the effectiveness of MAS for the treatment of OSA and determine if sleep apnea symptoms, cephalometric measurements and sleep study data are associated with MAS treatment outcome. We included 100 patients, 82 men and 18 women, mean age 47.9 ± 10.8 years, 57% with mild and 38% with moderate OSA. MAS are personalized and advance the mandible 75% of maximum protusion and provide approximately 5–10 mm opening vertically (between incisor edges). All patients had cephalometric evaluation and nocturnal sleep study at baseline and under treatment with MAS. According to the variation of respiratory disturbance index (RDI), with and without MAS, patients were divided into three groups: complete responders (if RDI with MAS was reduced to less than 5 events per hour), partial responders (reduction of 50% or more in RDI but remaining above 5 per hour) and non-responders (less than 50% reduction in RDI). The main symptoms of OSA were snoring (43%) and excessive daytime sleepiness (34%). There was a statistically significant reduction of Epworth Sleepiness Scale (ESS) with MAS. On the follow-up sleep study there was also a statistically significant reduction in RDI and increase in minimum oxygen saturation (MinSaO2) with MAS. Thirty-seven patients were considered complete responders, 31 partial responders and 32 non-responders. Comparison between these three groups revealed that they were not statistically different in terms of age, body mass index or ESS score. Eighty-eight per cent of patients referred clinical improvement with MAS. Patients without clinical improvement had statistically significant higher Body Mass Index, ESS score, RDI and apnea index and lower MinSaO2 with MAS. Reduction of RDI with MAS was also less in this group. With regard to the sagittal skeletal relationships, there was a statistically significant alteration in ANB angle, ANS-Gn and PNS-P with MAS. Patients with no clinical improvement had statistically significant lower SNB angle and higher ANB angle with MAS. There was an association between clinical response and clinical Improvement (p = 0.002). MAS is an effective treatment for mild and moderate OSA. Evaluation of Epworth Sleepiness Scale (ESS), nocturnal sleep study indices and cephalometric measurements could predict successful outcome.